Jacob Janssen ( 1779 - 1856 ) was a Polish painter. Jacob Janssen s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 6509.78 USD for An extensive view of the port of Zanzibar, Tanzania in 2004 to 91421.57 USD for VIEW OF SYDNEY in 2007 , based on the size and medium of the artwork.